Half and half gate

ABSTRACT

The present invention comprises a sewer water gate to be located at the opening to a subsurface catch basin of a storm drain system that will exclude trash and debris from the system while still permitting a flow of water, but which will partially open to allow full access for water and entrained material when the rate of flow is sufficiently high while still obstructing the flow of heavier materials.

FIELD OF THE INVENTION

A rotatable drain grate in an opening into a sewer system which when closed retains trash and debris upstream from the opening while permitting slow flow of water, and which pivotally opens when confronted with high rates of water flow to allow overflow water into the sewer while restraining the heavier debris.

BACKGROUND OF THE INVENTION

Storm drains such as are found in gutters and drainage channels, receive trash, cuttings, trimmings and other debris constantly throughout the year and are subject to clogging. Despite regular sweeping upstream from the opening, considerable amounts of trash will enter the drain system, while still permitting the slow flow of water. Ground water run-off frequently carries petroleum products with it. Such pollutants include oil, gasoline, greases, etc. that originate in streets, parking lots, service garages, etc. Pollution and contamination of waterways is damaging to human health and the environment. It is important to try to eliminate these pollutants from the water run-off before it reaches the water table. One physical property of these pollutants that can be exploited in trying to separate them from the water run-off is that most of them float (i.e., they are less dense than water). Prior efforts to remove such petroleum pollutants from water run-off have been less than completely successful. To maintain freshwater systems, most cities and counties have regulations that require the removal of some of the pollutants from the storm-water runoff before entering their storm sewer systems. In order to meet these regulations, facilities typically install on-site pollution traps to filter the storm-water runoff. These pollution traps are sometimes referred to as “oil/grit separators.”

Serious trouble arises when later storms or other circumstances present water to these systems at high rates of flow while they are congested with the accumulated trash. Clogging of this system can result in upstream flooding, or the washing downstream of the accumulated material. To avoid this situation, throughout the year maintenance crews are sent to clear out trash and debris that has entered the system through the openings. This is a considerable expense, and in the event that a storm strikes before the system is cleared, serious damage can occur despite those earlier efforts.

Most conventional pollution traps provide only “first flush” filtration during the typical local storm event, but permit bypassing the filtration stage for larger storms. In fact, many jurisdictions require bypassing, some even at typical storm water flows. Bypassing filtration is a problem because most pollutants are more easily picked up and transported by storm water during higher flow periods. Unfortunately, just when the traps are needed most, a lot of pollutants bypass them and are delivered into the storm sewer systems. And most pollution traps that do not provide for bypassing accommodate the larger flows because they are oversized, which adds significantly to the cost to build, install, and maintain them.

In addition, most filter systems included in the catch basin of storm sewer systems which, under low flow conditions, often act as biological incubators that add to the microbial contamination of storm water runoff. Such bacterial pollutants, unlike chemical ones, are dynamic, continue to grow exponentially, and may quickly reach dangerous level. Some filter systems use chemicals, which can be damaging to the environment.

Therefore, what is needed is a means to be installed in the drain opening of a catch basin of a typical storm drain system to trap, block or reduce the entry of unwanted leaves, litter and similar debris without interfering with the flow of rainwater through filtration system and into the storm sewer system. Also needed is a filtration system that will powerful, cost effective and durable system for water filtration with antimicrobial action.

SUMMARY OF THE INVENTION

Accordingly, it is an object of this invention to provide a sewer water gate to be located at the opening to a subsurface catch basin of a storm drain system that will exclude trash and debris from the system while still permitting a flow of water, but which will partially open to allow full access for water (and entrained material) when the rate of flow is sufficiently high while still obstructing the flow of heavier materials. When fully closed, the gate will permit the trash upstream from it to be removed by routine collection sweeping, so as to remove trash that otherwise would later be driven into the system by storm runoff. Another object of this invention is to provide a sewer water gate system that includes a filter system that reduces the buildup of microbial contamination from storm water runoff.

DRAWINGS

FIG. 1 is a front perspective view disclosing the water gate of the invention.

FIG. 2 is a top view of the water gate of the invention.

FIG. 3 is rear perspective view of the water gate of the invention.

FIG. 4 is rear perspective view of the water gate of the invention disclosing a filtration system.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, the gate system 100 of the invention comprises two side brackets 120 and 140, which when attached to a lower fixed screen 160 and upper screen section 180 comprise a frame to which upper gate 200 and rotatable means 230 are affixed. Side brackets 120 and 140 are 1¼″ angle iron braces of sufficient length to span the vertical distance between the street gutter and the top of the standard sewer drain opening. In this preferred embodiment side brackets 120 and 140 are constructed of 0.125″ 304 stainless steel.

Side brackets 120 and 140 are opposingly affixed to lower gate screen 160 by means of standard cap screws 165. Lower gate screen 160 is sized to span the horizontal distance between the left and right sides of a sewer drain opening, such that when gate system 100 is installed, lower gate 160 effectively blocks debris and other solid matter entering the sewer drain opening at the gutter level. In this preferred embodiment, lower gate 160 is constructed of 10-gauge, 0.75 inch expanded metal stainless steel. Also shown in FIGS. 1 and 2 are anchor plates 145, affixed to both side brackets 120 and 140, and which are used to anchor gate system 100 the opening to the subsurface catch basin. Positioned above lower gate screen 160 and spanning between side brackets 120 and 140 is upper bracket 180, comprised of a 1×1×0.125 inch stainless steel angle iron. Upper bracket 180 is affixed to side brackets 120 and 140 by standard stainless steel nuts and bolts, as would be obvious to one of ordinary skill in the art. The combination of side brackets 120 and 140 with upper bracket 180 form an upper frame for receiving upper gate 200 and rotatable means 230.

Upper gate 200 and rotatable means 230 form the rotatable gate portions of the water gate of the invention. In this preferred embodiment, rotatable means 230 is comprised on a standard hinge commonly known as a piano hinge, which is sized to substantially span the distance between side bracket 120 and side bracket 140 while permitting the hinge action to freely move without contacting either side bracket 120 or side bracket 140. Rotatable means 230 is also constructed of 1×1 inch stainless steel. Although rotatable means 230 is comprised of a piano hinge in this embodiment, such hinge is not a limitation of the invention, other types of rotatable means may be used, including other types of hinges, springs, or other devices. The only requirement is that the rotatable means be adaptable to being affixed to upper bracket 180 and to rotatably support upper gate 200. However, a hinge has certain advantages over a spring, that being that the hinge need not be manually reset. Upper gate 200 is comprised of 0.375 inch lexan-polycarbonite screen, having openings for the passage of water. As shown in FIG. 1, upper gate 200 has been formed with various sized openings, consisting of slots and pour holes. Although a lexan-polycarbonate material was used in this preferred embodiment, any material for upper gate 200 may be employed as long as the resulting gate is not so heavy that the gate does not rotate when a specified amount of water pressure and debris applies pressure upper gate 200. Such other material could be a 16-gauge, 0.25 thick stainless steel, or equivalent material.

Gate system 100 additionally includes bias means 240 for biasing rotatable upper gate 200 in a closed position. In this preferred embodiment, bias means 240 comprises a pair of magnets selected with sufficient magnetic strength to cause upper gate 200 to rotate to a closed position when the pressure of the water and debris drops below a selected level. Referring to FIGS. 2 and 3, limit brackets 210 and 215 are opposingly affixed to side brackets 120 and 140, respectively, and spaced intermediate to fixed lower gate 160 and upper bracket 180. Limit brackets 210 and 215 form a stop to restrain upper gate 200 from swinging street ward so that there would not be a potential for upper gate 200 to be blocked in an open position. In this preferred embodiment, permanent magnets 240 are mounted on opposing ends of upper gate 200, adjacent the left and right sides of upper gate 200. Permanent magnets 240 are vertically positioned such that they will oppose limit brackets 210 and 215, and such that limit brackets 210 and 215 also function as magnet stops. Limit brackets 210 and 215 are made from a galvanized, ferromagnetic material. In this preferred embodiment permanent magnets 240 are 1 inch diameter, 0.25 inches thick, with a coating of molybdenum epoxy, with a center hole of ⅜ inches, and affixed to upper gate 200 by means of magnet cap screw 245. Alternatively, magnets 240 could be mounted on limit brackets 210 and 215, and opposing paramagnetic metals affixed to upper gate 200 that would be attracted to magnets 240. Once water/debris pressure is removed from upper gate 200, gravity will bias upper gate 200 toward the closed position, and magnetic attraction will induce upper gate to seat against limit brackets 210 and 215. Bias means 240 is not limited to ferromagnetic devices such as magnets. Other means of biasing upper gate 200 in a closed position would be well know to ones of ordinary skill in the art, such as coil springs, leaf springs, etc. Alternatively, the piano hinge of the preferred embodiment could be spring loaded to bias upper gate 200 against limit brackets 210 and 215.

Referring now to FIGS. 3 and. 4, filter bracket 270 is attached to the upper edge of fixed lower gate 160 by standard stainless steel nuts and bolts, as would be obvious to one of ordinary skill in the art. Suspended from filter bracket 270 is filter means 280. In this embodiment, filter means 280 is comprised of a plurality of filter strips 285 fabricated from membranes. Filter strips 285 are fabricated form X-Tex anti-microbial filter media that kills or inhibits the growth of microbes such as bacteria, fungi, or viruses so that such microbes will not enter the sewer system. Membrane filters are constructed in very thin layers from polymers and other advanced synthetic materials. Membrane filter thickness varies from 100 to 300 micro-meters, and are usually designed and manufactured with approximately 70 to 90 percent porosity. Membrane filters are commonly manufactured from MCE (nitrocellulose), Cellulose Acetate, Coated PTFE (Teflon), Hydrophobic PTFE, Nylon, polycarbonate, or glass. The invention is not restricted to any particular anti-microbial material, and any other anti-microbial material may be employed.

Although preferred embodiments of the invention have been described herein in detail, it will be understood that those skilled in the art can make modifications thereto without departing from the spirit of the invention or the scope of the appended claims. For example, filter means 280 could also be comprised of a material that absorbs hydrobarbons. 

1. A gate system to be located at the opening to a subsurface catch basin of a storm drain system, the opening having a given height and width, the gate system for blocking leaves, litter and other debris from entering the catch basin, the gate system comprising: (a) a gate frame sized to substantially occupy the catch basin opening, the gate frame consisting of a pair of parallel side brackets connected to a lower gate bracket and to an upper gate bracket, the upper and lower gate brackets sized to span the width of the catch basin opening, wherein; (b) the lower gate bracket is comprised of a fixed gate to obstruct the passage of debris; and (c) the upper gate bracket having rotatable means for receiving an upper gate, the upper gate to obstruct the passage of debris, and wherein when a specified pressure of overflow water and debris impacts the upper gate portion, the upper gate portion will rotate to an open position, permitting water and debris to flow over the fixed lower gate and into the catch basin.
 2. The gate system of claim 1 wherein the fixed lower gate is perforated to permit the flow of water into the catch basin.
 3. The gate system of claim 1 wherein the rotatable upper gate is perforated to permit the flow of water into the catch basin
 4. The gate system of claim 1 wherein the two parallel side brackets additionally include means for bracing the upper gate portion in a closed position.
 5. The gate system of claim 4 additionally including bias means for biasing the rotatable upper gate against the bracing means.
 6. The gate system of claim 5 wherein the bias means is selected number of magnets having a selected magnetic strength.
 7. The gate system of claim 1 wherein the rotatable means is a hinge sized to substantially span the width of the catch basin opening.
 8. The gate system of claim 1 additionally including filtration means extending from the lower gate portion into the subsurface catch basin.
 9. The gate system of claim 8 wherein the filtration means is constructed of an anti-microbial material.
 10. A gate system to be located at the opening to a subsurface catch basin of a storm drain system, the opening having a given height and width, the gate system for blocking leaves, litter and other debris from entering the catch basin, the gate system comprising: (a) a gate frame sized to substantially occupy the catch basin opening, the gate frame consisting of a pair of parallel side brackets connected to a lower gate bracket and to an upper gate bracket, the upper and lower gate brackets sized to span the width of the catch basin opening, the parallel side brackets including means for bracing the upper gate portion in a closed position, wherein; (b) the lower gate bracket is comprised of a fixed perforated gate to permit the flow of groundwater while obstructing the passage of debris; and (c) the upper gate bracket having rotatable means for receiving an upper gate, the upper gate having perforations to permit the flow of groundwater while obstructing the passage of debris, and wherein when a specified pressure of overflow water and debris impacts the upper gate, the upper gate will rotate to an open position, permitting water and debris to flow over the fixed lower gate and into the catch basin.
 11. The gate system of claim 10 including bias means for biasing the rotatable upper gate against the bracing means.
 12. The gate system of claim 11 wherein the bias means is a selected number of magnets having a selected magnetic strength.
 13. The gate system of claim 10 wherein the rotatable means is a hinge sized to substantially span the width of the catch basin opening,.
 14. The gate system of claim 10 wherein the rotatable means is a selected number of hinges spaced along the upper bracket.
 15. The gate system of claim 10 wherein the rotatable means is spring loaded.
 16. The gate system of claim 1 additionally including filtration means extending from the lower gate portion into the subsurface catch basin.
 17. The gate system of claim 8 wherein the filtration means is constructed of an anti-microbial material.
 18. The gate system of claim 8 wherein the filtration means is constructed of a hydrocarbon absorption material.
 19. A gate system to be located at the opening to a subsurface catch basin of a storm drain system, the opening having a given height and width, the gate system for blocking leaves, litter and other debris from entering the catch basin, the gate system comprising: (a) a gate frame sized to substantially occupy the catch basin opening, the gate frame consisting of a pair of parallel side brackets connected to a lower gate bracket and to an upper gate bracket, the upper and lower gate brackets sized to span the width of the catch basin opening, the parallel side brackets including means for bracing the upper gate portion in a closed position, wherein; (b) the lower gate bracket comprised of a fixed perforated gate to permit the flow of groundwater while obstructing the passage of debris; (c) the upper gate bracket having rotatable means for receiving an upper gate, the upper gate having perforations to permit the flow of groundwater while obstructing the passage of debris; (d) the lower bracket additionally including filtration means extending from the lower gate bracket into the subsurface catch basin; (e) the gate system including bias means for biasing the rotatable upper gate against the bracing means; and wherein when a specified pressure of overflow water and debris impacts the upper gate, the upper gate will rotate to an open position, permitting water and debris to flow over the fixed lower gate and into the catch basin.
 20. The gate system of claim 19 wherein the bias means is a selected number of magnets having a selected magnetic strength.
 21. The gate system of claim 19 wherein the rotatable means is a hinge sized to substantially span the width of the catch basin opening,.
 22. The gate system of claim 19 wherein the rotatable means is a selected number of hinges spaced along the upper bracket.
 23. The gate system of claim 19 wherein the rotatable means is spring loaded.
 24. The gate system of claim 19 wherein the filtration means is constructed of an anti-microbial material.
 25. The gate system of claim 19 wherein the filtration means is constructed of a hydrocarbon absorption material. 